3. DEFINITION Closed-angle glaucomas are characterized by a shallow anterior chamber that forces the root of the mid-dilated iris forward against the trabecular network, obstructing the drainage of aqueous humor and thereby increasing the intraocular pressure. Groups at Risks Age >60 years Gender: females > males (4:1) Race: Asians Family history: increased risk with 1st degree relatives
8. PHYSIOLOGICAL PUPILLARY BLOCK 1. Iris has large arc of contact with anterior surface of lens 2. Resistance to aqueous flow from posterior to anterior chamber (relative pupil block) 4. Iris lies against trabecular meshwork impede aqueous humor drainage ↑ IOP 3. Pupil dilates, peripheral iris becomes more flaccid and pushed anteriorly
9. SYMPTOMS Rapidly progressive impairment of vision Painful eye Red eye Nausea, vomiting Photophobia Haloes, transient blurring – indicate previous intermittent attacks Hx of similar attacks in the past, aborted by sleep ** CACG: usually asymptomatic due to slow onset of disease
10. SIGNS Reduced visual acuity Cornea cloudy and oedematous Pupil oval, fixed and moderately dilated Ciliaryinjection Eye feels hard on palpation Elevated IOP (50-100 mmHg) Narrow chamber angle with peripheral iridocornealcontact Aqueous flare and cells Gonioscopy– complete peripheral iridocornealcontact Ophthalmoscopy– optic disc odema and hyperaemia
14. Corneal trauma or infection Acute congestive glaucoma Acute iridocyclitis Acuteconjunctivitis Common Uncommon Common Extremely common Incidence Watery or purulent None None Moderate to copious (mucopurulent) Discharge Usually blurred Markedly blurred Slightly blurred No effect on vision Vision Moderate to severe Severe Moderate variable Pain DIFFERENTIAL DIAGNOSIS
15. Diffuse Diffuse Mainly circumcorneal Diffuse, more toward fornices Conjunctival injection Change in clarity related to cause Hazy Usually clear Clear Cornea Normal Semidilated and fixed Small Normal Pupil size Normal None Poor Normal Pupillary light response Normal Elevated Normal Normal Intraocular pressure Organisms found only in corneal ulcers due to infection No organisms No organisms Causative organisms Smear
16. MANAGEMENT Emergency treatment is required – preserve the sight! Prevent adhesions of peripheral iris to trabecular meshwork resulting in permanent closure of angle I.V acetazolamide500mg followed by oral acetazolamide 250mg qid after acute attack has broken Topical beta-blockers Topical steriodsfour times daily to lower the intraocular pressure and decongest the eye
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18. SURGICAL MANAGEMENT Peripheral laser iridotomy (LPI) (YAG Laser) To establish the communication between the posterior and anterior chambers by making an opening in the peripheral iris This will be successful only if less than 50% of the angle is closed by permanent peripheral anterior synechiae Peripheral Iridectomy
19. CX AND SEQUALAE Peripheral anterior synechiae (PAS) – the peripheral iris adheres to the posterior corneal surface in the trabecular area and blocks the outflow of aqueous Cataract- swelling of the lens and cataract formation – this may push the iris even further anteriorly; this increases the pupillary block Atrophy of the retina and optic nerve - glaucomatous cupping of the optic disc and retinal atrophy Absolute glaucoma - eye is stony hard, sightless, painful
20. SECONDARY ANGLE CLOSURE GLAUCOMA Angle-closure secondary to a variety of ocular disorders Lens abnormalities (thick cataract) Lens dislocation Inflammation (uveitis, scleritis, extensive retinal photocoagulation) Signs and symptoms Same as PACG